Method of and apparatus for correcting deviations in crossrails of machine tools



Dec. 28, 1948. L. L. HERCIK r 2,457,468

METHOD OF AND APPARATUS FOR CORRE CTING DEVIATIONS IN CROSS-RAILS OFMACHINE TOOLS 4 Sheets-Sheet 1 Filea Dec. 31, 1945 5 12 4 Hal.

Arronwe'v.

Dec. 28, 1948. L. HERCIK 2,457,468

' METHOD OF AND APPARATUS FOR CORRECTING DEVIATIONS IN CROSS-RAILS OFMACHINE TOOLS Filed Dec. 31, 1945 4 Sheets-Sheet 2 'llvvelvro'p [A0 ZHERC/K Ar TORNEY L. L. HE-RCIK Y Dec. 28, 1948.

. METHOD OF AND APPARATUS FOR CORRECTINQDEVIATIONS IN CROSS-RAILS OFMACHINE TOOLS Filecl Dec.

4 Sheets- Sheet 3 Array/vs).

Dec. 28, 1948. HERCIK 2,457,468

' METHOD OF AND APPARATUS FOR CORRECTING DEVIA'IIONS Y IN CROSS-RAILS OFMACHINE TOOLS Filed D60. 31, 1945 4 Sheets-Sheet 4 31 32 I 9 25 3 6 {622 5 :2 33 g 25 'l' V A l #1 A T J 5 L 15 O J 3) J a /2 2- //VVENTO,Q

L40 1 HE/Pc/K Arrok/vfy- Patented Dec. 28, 1948 PATENT O FiFll CiEMETHOD ';0F,AND; APPARATUS FOR eon- ;nnczcmo -DEVIATIONS.JN .GROSSRAILSoF f uncmnntroons This "invention relates :generally to machine tools,and more "particularly toapparatus "for and'ineth'ods for .correcting"deviations from a rectilinear form which occur *in "rails .or ways of'ma'chin'e tools vvhich-are"traversed by tool car- *r'iages during thefinishing operations 'on'the'work "by finishing tools.

While the herein'discl'ose'd inventionis adapted for use with'manytypesof imachinejtools, its

advantages "are roost clearly apparent when his embodied in surfacegrinding machines "the type 'which "are adapted ffor "grindingrelatively Wide surfaces, and'accordin'gly the invention is *illustratedand describedhn connection with a *grinding" machine of this character.

-Machineso'f thistype usually-eomprise'atravelling work support such "as"a :platen ortable, and supporting columns 'or uprights, located pm eachside thereof, andwidely-spacedapartguponwhich columns "are mountedcross-rails 'or ways amen extend between andfbey ondthe columns. Thesecross-rails "or ways "carry a travelling tool head carriage and itsrelated parts, including a gi'ind- 'ing wheel, its mounting, and adriving v motor.

All parts of the machine 'ar e "of 7 heavy construc- 25 tion, and thetool head and its 'related "parts-likewvise pr'oportionatelfheavyin-most types ofmachines, necessarily project to 'one side "on *thecross-rails or ways, resulting in "an overhanging "or pverbalancedcondition. This overhanging tool'head carriage imposes t'wisting 'ordeflecting --strains "upon ;the rails: or ways, causing deviations :fromthe intended rectilinear "form of the rails and =correspondingdeviations "from "the intended straight line travel of the toolheadand'particu- 5 of -'an inch, and when "transmittedto the "workirender the same '-uns'atis'factory or 1 unfit 'for "the purposeintended.

iIt "might =appear that 'an increase in the cross sectional areas-of'the m'etalin the cross-rails or ways would .eliminate the:di'fficulties, "but experi- .ments have'shnwn thatieven in muchiheavier :metal sectiims, Ltlrere is ssuificientdeflection orl'5'Gla'ims. (01551- 16 6) does not lie inthis direction, even if thegreater expenseandcxcessive'weightsinvolved, are overlooked.

An objector thegpresentinvention, therefore is to provide "an economicaland efii'cient method and apparatus 'for rectifying deviations fromstraight line traveldf 'a tool head,as of a'grinding machine, with'refere'nce t'o the'work or work sup- "port, and thus eliminatetransmission of such deviations to the finished w'ork.

Another object of the invention is "to providea'method-andapparatus"for-adjustably correcting deviations in thetraveler a tool head, which may be caused-by imposition "df twisting ordeflecting load stresses upon *the 'cross r'ails or ways along which thetool head travels.

stillanother'ob'ject'df theinvention'is to provide "a method andapparatus for prede'terniining the amount and "location-oi "suchdeviations, and adjustably'corre'ctingthe same toinsure straight linetravelof the'tool head with respect to the work support.

hiurther'objec't of thisinventionis to provide am'ethod and apparatusfor'correctin'g deviations in straight line travel of a toolhead,'both'between and 'fbeyond the supports forthe "cross-"rails orways alongiwhich the toolhead travels.

Astill further object df 'theinvention'is to pro- "vid'e-a method andapparatus'for correcting-deviations inthe'travel of a tool head,vvhereinone adjus'tmentsufiicesto :condition the machine for extensive operationwithout readjustment.

further understanding of "the construction and operation and of themanner in which the .novel fe'a'tur'es of .th'isinvention effect theabove and further objects, willbecome 'apparent from "the followingdetailed description and the an- ;neflxed drawings, which setfforthmeans embodying this invention, s'uchdisclose'd means constituting,,however,,but oneof the forms in which 'the principle. of this inventionmay be applied.

' "Referring "to the annexed drawings:

Figure '1 is a iront elevational, part sectional view .of adouble'hduslihghor-iaontal surface grind- .ing machine embodying-thisinvention, this View heingta-ken transversely-thru the bed ofthe-machine i-acingthe irontroftheuprights of the housring onfthelplan'esubstantiallyindicated by lines l, ifinzFigures 3 and-ii, a portion'ofthe view'being :broken away to bttervaceommodate the same to ihe :sheet.

Ei'guiie 12 is za;re'ar Iele'vational, :part sectional mew iOf rsaidsurface. grinding .;machine, :this view 55 :beingitazkenztransvers'elyihrusthezmachine facing the rear of the uprights, on the planesubstantially indicated by lines 2, 2 in Figures 3 and 4.

Figure 3 is a plan sectional view of this surface of this surfacegrinding machine, partly broken away, this view being taken from theplane indicated by lines 5, 5 in Figure 1.

Figure 6 is an enlarged view of a portion of Figure 4 comprising afragmentary vertical sectional view thru the cross-rail of the grindingmachine and showing associated parts of the cross-rail rectifyingdevice. f

Figure 7 is an enlarged fragmentary plan sectional View illustrating therelation between one 4 elements not being shown in detail, as they donot form part of the present invention.

The saddle 23 is mounted for horizontal reciprocation upon a cross-railor transverse track member 25. The rail member may be in the form of askeleton or hollow casting, which has upper and lower spaced rails orways 26 and 21, connectedintermediate their ends adjacent and forwardlyof the columns E'and'l by web members 39 and at their ends by integrallyformed webs, one of which is shown at 28. The rails 26 and 21, as bestshown in Figure 1, extend between the'columns 6 and I, and considerablybeyond said columns especially on the left side of the machine, asviewed in Figure l. The

(upper rail 26 is preferably formed as an upwardly directed flange 29,providing a slideway upright of the housing of the grinding machine andthe cross-rail and its associated rectifying devices, this view beingtaken on the plane indicated by lines l, 'l in Figures 1 and 2.

Figure 7a is a similarly enlarged fragmentary plan sectional viewillustrating the relation between one upright of the housing of thegrinding machine and the cross-rail and its rectifying devices, thisview being taken on a plane indicated by lines 1a, 1a in Figures 1, 2and 6, this plane being slightly below the plane of Figure '7.

As shown in the drawings, the surface grind ing machine in which thisinvention is embodied comprises a pair of widely spaced heavy columns oruprights 6 and 7, relatively deep fore and aft, hollow in cross section,and connected at their tops by cross members or tie pieces 8. Theforward edge of each of the columns 6 and 'l is of channel shapedconformation in transverse section, closed at top and bottom by wallsea,

9b, respectively, and having inwardly and outwardly turned verticallyextending flanges l0 and l l at the forward edges of the legs of thechannel conformation, all for a purpose pres,- ently to appear.

Arranged between the lower ends of the columns 6 and l, is an elongatedbase casting l2, having longitudinally extending spaced V-grooves orways is, adapted for the reception of slide tongues l4, V-shaped incross-section and forming part of a work carrying table or platen IS.The table i5 is adapted to be longitudinally reciprocated by anysuitable mechanism, not shown in detail, hydraulically actuated means ofa well known type usually being employed for this purpose. While manytypes of work may be processed on this surface grinder, a machine basecasting A is shown, for purposes of illustration, in dot and dash lines,supported upon the table [5.

Mounted to reciprocate transversely across and above the table l5 andthe work A, is a tool head carriage IS. The tool head carriage Itincludes a tool head IT, a grinding wheel 3, the

latter being driven by a motor l9, thru a belt- 20, these and relatedparts being carried by a slide or support 2i. The slide 2| is mountedfor vertical adjustment on slide ways 22 which slidably engage the slide2! with a tool head saddle 23. Vertical adjustment of the tool head I!with reference to the tool head saddle 23 is effected thru manipulationof a vertical worm shaft 2d engaging a nut 24a, which vertical shaft is,in turn, actuated by a horizontaI shaft 24b, the interconnection ofthese tool head adju ing 30, upon which an' inwardly directed angularflange 3! of the saddle 23 is adapted to bear, an adjustable liner stripor gib adapted to compen- Sate ,for wear, being interposed between thebearing surfaces, and a' retaining piece 32 extending behind the flange29.v The lower rail 21 provides a slideway upon which bears anadjustable gib supporting a shoulder 33 formed at the inner sideof thesaddle 23, and below the slideway the rail 2! is provided .;with.adownwardly directed flange 34, of considerably greater depth than theflange 29, the front face of which is formed .toprovide an undercut ordove tailed beveled slideway 35, for the reception of acorrespondinglyshaped shoulder 36 formed along the inner side of thesaddle 23. For the manual transverse adjustment of the saddle and toolhead, a worm shaft v3'! is provided extending longitudinally thru thecross-rail casting 25 and engaging a disconnectable nut portion 23amounted on the saddle 23,,each end of the shaft 31 being formed with asquare so that it may be engaged by a suitable crank handle wrenchwhereby the shaft may be .manually rotated. This manual rotation of theshaft 31 effects sliding reciprocation of the tool head saddle 23 alongthe rails or slideways 26 and 21. The progressive lateral reciprocationof the tool saddle in both directions during the regular productiongrinding operation of the machine is effected by hydraulic meansincluding a cylinder 23b shown in Figures 1, 4 and 6, this hydraulicactuating means being well known inthis type of machine tool andforming, per se, no part of this invention, need not be furtherdescribed in detail.

,When the tool carriage is hydraulically actuated comprisesa rearvertical web section 25a and upper and lower flange sections 25b and 250integrally connected at their front edges with the rails 26 and 27!,respectively. The ends of the channel formation terminate in verticallyextended walls; 38,, 38.. Each wall 38 is integrally connectedwith a webportion 39 adaptedto bear upon the faces of the flanges II], II of thecolumns 6 and I. Each web portion 39 is connected with a flange 48,Figures 1 and 3, to provide a vertically extending channel formationwhich slidably fits. over the forward edge of each of the columns, theflanges 40 bearing upon the outer flanges H, H of the columns 6 and 1,and in each case a retaining piece 4! is provided behind the relatedflange H. The cross-rail member 25 is thus mounted for verticaladjustv:ment, and iswadapted atofbe wertieally adjusted thru the mediumof vertical adjusting screws .or warm ishafts -42 engaging :nut pieces43 tmounted -on .the web :p'ortion $39, :the sshaits 42 being adapted tobe ":driven iin zunison: by :a rmntor M, Ythnu :shafting Ma and gearingindicated generally at 4427. Mechanism :forcounter-balancing ithe.Wlig'ht :of ithe cross-rail and dissociated parts ziscadditionallyprovided iin order ito reduce the .power required :to iraise tthe:crosserail and "associated parts. This i counterbalancing mechanismxincludes: a counterweight; cable"! 5a, forcemdltiplying rdrum M152)end-compensating 'cable -'take up mechanism indicated generally at 450.This motor M and associated-drive parts and the counterweight 45 andassociated mechanism, Tforming no part of this invention, per se, neednot be "here described in' detail. This drive and 'counterbalanc'ingmechanism are, however, described incompletedetail inmy co-pendingapplication 1 Serial 'No. 6 38 ,529, entitled Counterbal- *ancingmechanism formachine tools, -and filed *December'Bl, 1945, now PatentNo. 2,434,613, issuedJanuary' 13, 1948.

'Iiaterally outwardly beyond the flanges '40, Figures 1,2 "and '7,itqand'bottom walls 46 and 41, shown'horizontally alined'with the'walls band "250, continue toward and merge with the end walls128. Thisoutwardly extending section is also channel shaped in verticalcross-section, the horizontal walls 46 and 41 being connected by avertical web T48. An additional wall extensionor ,flangeffla IisIformedat the extremefbottom of this, outwardly extending section .ofthe cross- .rail. member, this .flange .being below and spaced from thewall .41, andrconnected with the out-- wardly extending .portion .of the:flange 34.

.Assuming the use .of .the.flnest materials, precision preparedcross-.rail surfaces and general excellence of construction, operationofthemech- .anism.thus far described results inimparting to the. uppersurface of the 'flnished work, suchas .ishown at A,.a contour,exaggerated for the ipur- ,poses of illustration, conforming to .thecurved .brokenlline shown at 48,58, .and 51 in Figure 1. 'This contourresults from forces setup-generally along thelines indicated ,bythearrows .-B and C as shown in Figure 4, due to the weightandoverbalanced condition of .the tool carriage and .lWh-en the tool saddle"2 3, in

Litsrlated parts. "its traverse of the .work, travels on .theextreme.xleftgEi -gure 1, of the crossrail\member.25, some .downwardsag .and.tWist or deflection occurs in theiportionof ithewvways 26' and.2'l ofthe crosserail .extendinglaterallyoutwardlyvbeyond the column L6 becauseof .the Weight .and ioverbalanc-ed Eposition .of the tool carriage, justtreferredtto, produc- ,ing a contour in the finished surface of l thework ..of the character :indicated .at 49. When the 'toolcarriagepasses-thecolumn 16, the supporting effect, of I .the column on the ways'26 and ,-2 1 of .the cross-rail 25 reduces-:or eliminates :thesa'g T01deflection of the rail and produces :a slight :rel-

eativetrisein the contourof thefinishonthe work, of the character.indicated A at 59.

Whenathe tool carriage travels-on ,the ways 26 aandiz'l of :that

sportion of the cross-rail -member 25 between zthe columns-J5 and :1,greater sag or'deflection again ..progressively occurs as the l carriage:tr-avels along y 33$ 5 I 'These-deviations:in'travelof :th'e toolheadand grinding --wheel "or rather :tool, zalthoughtheir ill) ilesssometimes )in :excess .of :ten one-thouwsandths of-Lan vinch, and .occurL130 an appreciable sextentiregardl'essof how'heavy or rigidtheconstructiomof :the cross-rail mayrbe. ThisLis par- -ticularly=truewhen .the tool consists of a large grinding wheel driven by a highpowered motor which is necessarily of substantial size and weight.

For counteracting and rectifying this conditi'onjl'.employ-an'expedientwhich includesthe application of adjustable forcescounter to the forces which cause 1 the "fl-exures resulting in thedeviations in the path of travel of the tool, which enables me to'rectify and direct the travel "or the tool to a path-substantiallyexactly parallel '-tothe'p1ane 'of 'the work table top.

"since the'deviations occur between the columns 6 and 'l'and laterallyoutwardlyof the column-6, particular and-separate-means are employed tomeet thiscon'dition in these two areas-of the cross-rail.

=Thesemeans, for correcting the deviations betweenthe-columns Gand '1,include an angle bar 52 arrangedbeneath'the cross-rail member "25,"the-angle bar 52 comprising flanges '53 and5'4, connected at theiropposite ends by integrally 'formed endwalls '55. The angle bar 52 is ofan overall length so as-tonic'elyfit'between the verticallye-xtendedwalls '38, 38 of the cross-rail member 25, and 'is fixed inplace by screw bolts '56 'threaded'thru the end walls andinto'the-adjacent walls 38, 38.

The angle-bar ti, once fixed in position, has its flange-53disposedparallel to and inthe rear of the'flan-ge '34 and rail 2l'of thecross-rail member 25, and is'spa'ced a slight distance from the flangeExtended thru the 'flange 53 is a series of in'dividual'adjustingmembers, preferably in the form o'f =setscrews-'5l, which are threadedthru the flange 53a-t intervals therealong, and in such position thattheir inner ends are adapted'to bear upon the inner facesof the flange'34. The set screws 51 are provided with heads readily ac- :cessibleformanipulation thru use-of a suitable tool. When 'the-screws 5? are turnedforwardly theyssetiupaforces upon the inner surface of the tfiange .311.in a direction counter to the forces :indicated by the arrow C, Fig. 4,tending to straighten or to: counterflex the latter to whatever:extentit is deflected from the original or intended rectilineariform,and thus to true or re- .=store :t'hedntended rectilinear configurationof the raillflange :34 and rail :proper or way 21.

Also lthreade'd thru the flange 54 of the angle bar '52- is z-a seriesof set screws 155, arranged at intervals therealong, having their headsacces- :=sibl'e iforiready:manipulation, and havin their :inner :ends1bearing upon the adjacent bottom ,svallzzficcoisthe u-ishaped'se'ctionofthe cross-rail ,mem'berilfi. The screws 5$ are operable to resistithelreacti'on imposed by the screws 5'5 upon'the 11113113653 01theiangl'e bar 52, "and to exert vertical .zforces counterztoithe forcesacting in'the direction of the arrow B, thereby straightening oricounterflex-ing the flange 3 3 and the rail 21 in a :verticaldirection.

:F'or counteracting "and rectifying sag or vdevization inithatportionoftthe cross-rail member 25 extending outwardly to the left beyond thecolzumnaixaslviewed in Figure 1,'the cross-rail mem- --beri25is-provided between'the horizontal wall 4 1 and the 'h'orizontaltfiange41a, with an ear :62 this :earibein'glocated adjacently juxtaposed to,but tslightly: spaced :from the flange 40, and integrally efiect isexaggerated in thecdmwingnneventheiformediwithztheway alpas best shownin Figures enemas 2, 3, 5, 6 and 7. A set screw 63 is threaded thru theear 62, the inner end of which set screw is adapted to bear upon theadjacent flange 4130f the cross rail member 25. By reason of thelocation of the set screw 63, turning the same forwardly against theflange 40 serves to tilt the lower portion of the cross-rail member 25extending beyond the column 6 and particularly the lower rail 21 thereofin a forward direction, thus serving to tilt the entire overhangingportion slightly so as to counteract forces operating in the directionof the arrow C and effect the necessary counter-flexure in this portionof the crossrail member 25, in order to produce. the intended path oftravel of the face of the tool l8.

In truing up the cross-rail member 25, with reference to the table I5,and the work carried thereby, trial runs of the tool carriage over awork piece are made, and deviations are noted with the use of suitabletools, and then the appropriate set screws in line with such deviationsare adjusted primarily to correct deviations occurring because oftwisting or deflecting forces in the direction of the arrow C, while theset screws 59 are adjusted primarily to correct deviations caused byforces acting in the direction of the arrow B, the set screws 51 and 59,however, having a cooperative relation, and aiding one another in thetruing operation against a composite pattern of the distorting forcesdescribed. Likewise, during these trial runs, the set screw 63 isadjusted to correct the deviations occurring on the portion'of thecross-rail extending outwardly beyond the supporting column 6 as aresult of the twisting or deflecting forces caused by the weight of thetool carriage and indicated by the arrows B and C. It has been foundthat in practice, one screw is ample to produce the desired correctionin this extending portion of the cross-rail. It will be clear that, bythe method outlined the cross-rail may be restored to and maintained inits original rectilinear state, that is, in its intended rectilinearform, when it is subjected to the distorting and deviating stressesresulting from the unbalanced loads of the tool carriage.

It will be understood, from the above that the form of the ways 26 and21 of the cross-rail, when the cross-rail is not subjected to thedistorting and deviating stresses imposed by the tool carriage, may notbe, and usually is not, straight and rectilinear, the cross rail havingbeen preflexed from the rectilinear form to such an extent that thecross-rail will assume a substantially rectilinear form when the portionof the cross-rail in question is subjected to the load of the stressesof the carriage.

In its broader concept, the rectifying means described are not limitedto counteracting the deviating forces imposed upon the cross-rail. Thisrectifying means may, as will be understood, eifectively be used tocorrect such distortion as occurs in long generally rectilinear membersas a result of temperature changes, aging or release of initial strainsin such members.

It will be apparent that thru the use of the adjusting screw 57, theadjusting screws 59'and the adjusting screw 63, sagging, deviation ordeflection along the cross-rail members 25 and the rails thereof, andwith respect to the work table, may be accurately corrected so as toprovide rails or ways for the tool head carriage which will insurerectilinear travel of the tool in a plane substantially exactly parallelwith the faceof the work table and the work carried thereby, and thuseliminate inaccuracies in the contour of the work 'such as thoseindicated at'49, 50 and 51in Figure fications ofv the particularembodiment'of the invention herein shown and described for purposes ofillustration, maybe made without departing from the spirit of theinvention. It is to be noted that certain details disclosed in thisapplication but not claimed herein are claimed in my copendingapplication SerialNo. 638,529, filed December'31, 1945, entitledCounterbalancing mechanism for machine tools, now Patent No. 2,434,613,issued January 13, 1948..

WhatIclaim is: v v 1. Apparatus of the character described, comprising:elongated continuous suspended crossrail means having supportingmeansrestricted'to a localized area along its length, and having also anunsupported portion'extending beyond said supporting means, acarriagemovable on saidunsupported portion and subjecting the same to.deviation under load stresses from the intended rectilinear form ofsaid cross. rail means, and a rectifying device carried by saidcross-rail means and including means operable toexert aflexing forceupon said unsupported portion of said crossrail means, said flexingforce being exerted counter to said load stresses, 'thus to flex theunsupported portion of the cross-rail means to its intended rectilinearform when subjected tosaid load stresses.

2. Apparatus of the character described, comprising: elongatedcontinuous suspended crossrail means having supporting means at alocalized area along its length, and having also an unsupported portionextending beyond said supporting means, a carriage movable on saidunsupported portion and subjecting the same to deviationsunder loadstresses from the intended rectilinear state of said cross-rail means;and a rectifying device having a plurality of means selectively openableto exert, upon predetermined parts of the 'flexures under load stressesfrom the intended rectilinear form of said cross-rail means; anda devicecarried by said cross-rail means having a plurality of force exertingmeans independently operable to exert upon said unsupported portion ofsaid cross-rail means at the points of fiexure,

selectively variable forces for flexing the samein a counter directionsufficient to' compensate for the imposed flexures when said unsupportedportions are subjected to said load stresses. p

4. In a machine of the character describedya vertically extendingsupporting column, cross-rail means supported by said column andhaving'a portion extending beyond said column and formed with spacedways adapted to slidably support/a tool head carriage, said carriageexerting a turning influence on said extending portion of the cross-railabout a longitudinal axis thereof, and screw means associated with saidcross-rail means adapted to angularly flex one of said ways with respectto the other. e

5. a machine of the character described,

spaced vertically extending-supporting colums;

crossrail-means-supported by said columns, and. extendingbetweenandbeyondsaidcolumns, and adapted to betraversedby'atool headcarriage, said crossrrail meansbeing;susceptible,;under the load of saidcarriage, to progressively yariable sagging at. variouspoints alongitslength; and means for truingthe said cross-rail means to removesaidsagging therefrom,said truing means including a, plurality of elementsindependently operable =to-variably. flex saidzcross-rail means at thevarious points to. adjustably counteract .those forces causing saggingatthevarious points along said cross-rail means.

6. Iir-amachine of tlie character describedspaced: vertically extendingsupporting columns; elongated cross-rail means supported by saidcolumns, and extending between and beyond said columns; a tool headcarriage mounted upon said said cross-rail means, projecting to one sidethere of, and exerting a turning influence upon said cross-rail meansabout a longitudinal axis thereof; and rectifying means operable toexert a force counteractive to the turning influence upon saidcross-rail means.

7. In a machine of the character described, spaced vertically extendingsupports; elongated cross-rail means extending between said supports; atool head carriage adapted to traverse said cross-rail means, andprojecting to one side thereof; said carriage in its traverse of saidcrossrail means exerting a downward influence upon said cross-rail meansand also a turning influence about a longitudinal axis thereof; and acorrective device associated with said cross-raiI means, and including afirst power means operable for resisting said downward influence, and asecond power means for resisting the turning influence upon saidcross-rail means.

8.1n a machine of the character described, spaced vertically extendingsupports; elongated cross-rail means extending between said supports; atool head carriage adapted to traverse said cross-rail means, andprojecting to one side thereof, said carriage in its traverse of saidcrossrail means exerting a downward influence upon said cross-rail meansand also a turning influence about a longitudinal axis thereof; and acorrective device associated with said cross-rail means, and including afirst power means having a plurality of selectively operable elementsfor resisting said downward influence, and a second power means having aplurality of elements selectively operable to resist the turninginfluence upon said cross-rail means.

9. In a machine of the character described, cross-rail means havingmeans by which the same may be supported at spaced points therealong,said cross-rail means comprising a body portion carrying the rail meansproper; and a truing device carried by the said cross-rail means andextending the supporting means thereof, and having means for exertingforces upon said cross-rail means to counteract forces tending to causedeviation in the intended configuration of said crossrail means proper,when the latter is under load, said truing device including an angle barhaving its end portions secured to said cross-rail means adjacent to thesupporting means thereof, and having a plurality of adjusting membersthreaded at intervals thru each leg of said angle bar and adapted tobear upon selected portions of said rail means.

10. In a machine of the character described,

vertically extending supporting column" means,- cross rail'meanssupported forvertical travel upon said column means, thecross-rail means being-formed with a-fiange-engaging at least one sideof said column means and also formed with horizontally disposedvertically spaced generally rectilinear ways-adapted tobe traversed byatool carriage, said Waysextending laterally outwardlybeyondthe flange,and f orce applying means as-- s-oci'atedwith the flange-and one-of thelaterally outwardly extending ways, adapted to flex said one laterallyextending way out ofrectilinearalinem-ent with the-remainder of saidways;

11,1111" a machine of the character described,- spaced verticallyextending supporting columns, a horizontally"disposed cross-rail havingfront, rea. ,top and bot-tom'portions and carrying-channePsliapedformations extending verticallyacross' its rear portion and adapted toslidably engage the front and at least one side of the supportingcolumns, said cross-rail member also having spaced horizontallyextending top and bottom ways adjacent the front thereof, said waysextending longitudinally between and laterally outwardly of saidchannel-shaped formations and adapted to be traversed by a tool headcarriage, and force applying means positioned adjacent to and rearwardlyof one of said ways and between one of said channel shaped formationsand one outwardly extending end of said cross-rail memher, said forceapplying means being operable to adjust the angular position of said oneway with respect to the adjacent channel shaped formation.

12. In a machine of the character described, spaced vertically extendingsupporting columns, a horizontally disposed cross-rail having front,

rear, top and bottom portions and carrying vertically extending columnsengaging means across its rear portion including a rearwardly extendingflange, said means and flange being adapted to slidably engage the frontand at least one side of one of the supporting columns, said crossrailmember also having spaced horizontally extending top and bottom waysadjacent the front thereof, said ways extending longitudinally betweenand laterally outwardly of said column engaging means and adapted to betraversed by a tool head carriage, a rearwardly disposed extension fixedto one of said ways at a point intermediate the fiange and the outer endof one of the outwardly extending ways of the cross-rail, and juxtaposedto said flange, and force applying means, associated with said flangeand said extension, said force applying means being operable to adjustthe angular position of said one way with respect to the flange.

13. The method of truing a continuous metallic tool carrying cross-railof a machine tool, comprising: mounting the tool on the cross-rail,locating a plurality of localized areas of deviations from the intendedconfiguration of said cross-rail caused by the tool and applying aseparate force directly to the cross-rai1 in each of the areas ofdeviation to flex the said crossrail in a direction to restore itsintended configuration.

14. The method of truing a metallic tool carrying cross-rail of amachine tool, which is supported at a localized area along its lengthand subject to torsional flexure from a rectilinear form at pointsspaced from the localized area by the weight of a tool supported on thecross-rail, comprising: mounting the tool on the cross-rail, determiningthe amount of flexure produced in 11 the rail by the weight of the tool,and adjustably counterfiexing the rail torsionally to return the rail toits rectilinear form.

15. The method of truing a metallic tool carrying cross rail of amachine tool, which is supported in a substantially horizontal plane ata localized area along its length and which is subject to differentkinds of fiexures, including torsion and straight vertical sagging fromthe intended rectilinear form, resulting from the load imposed by theWeight of the tool, at points variously spaced from the supporting area,comprising; mounting the tool on the cross-rail ascertaining the extentand kind of flexure produced at the variously spaced points and variablyadjustably flexing the cross-rail at said points in a direction counterto the respective torsion and sagging, whereby the cross-rail assumesthe intended 1' 2 rectilinear format the -said' points-when the toolissupported at these points.

REFERENCES CITED The following references are file of this patent:

UNITED STATES PATENTS LAD L. 'HERCIK."

of record in the Germany June 30, 19 3 2.

